Iron-in stiffening insert

ABSTRACT

An iron-in stiffening insert comprising a support carrying a multiplicity of dots of adhesive arranged thereon in a random pattern. This arrangement prevents a furrowed appearance or a moire effect. The dots are generally circular and the spacing between adjacent dots ranges from about 1 to 2.5 times the average diameter of the dots with the spacing between adjacent dots being within 20% of the average adjacent dot spacing.

l I l 1 3,914,493

[ Oct. 21, 1975 United States Patent Griiber et al.

[ IRON-IN STIFFENING INSERT Inventors: Adolf Griiber, Waid-Ofling; Kurt Tischer, Hemsbach, both of Germany 886,746 1/1962 United Kingdom [73] Assignee: Firma Carl Freudenberg, Weinheim an der Bergstrasse Germany Primary Examiner-Thomas J. Herbert. Jr.

Assistant Examiner-Bruce H. Hess [22] Filed: Feb. 8, 1973 Attorney, Agent, or Firm-Burgess, Dinklage & Sprung Appl. No.1 330,

[30] Foreign Application Priority Data Mar. 4 Germany............................ I972 Gennany............................

An iron-in stiffening insert comprising a support carrying a multiplicity of dots of adhesive arranged thereon Apr. 15

in a random pattern. This arrangement prevents a furrowed appearance or a moire effect. The dots are gen- O0 8 9Nr 13 oo 8 2 41 4 5 B 5 a 2 9 l n 8 m 2 n 4 u L m C G S L U i M H 5 5 .l .l.

eraliy circular and the spacing between adjacent dots ranges from about I to 2.5 times the average diameter of the dots with the spacing between adjacent dots 5 2 N 3 21.. 2 u 8. B 6 W4 l .1 m6 1 h c r a e S i o d l e i F .1 0O 5 it 56] Reierences Cited being within 20% of the average adjacent dot spacing.

UNITED STATES PATENTS 5 Claims, 2 Drawing Figures 3,098,235 7/1963 Gusman.... 161/148 X IRON-IN STIFFENING INSERT The invention relates to a novel stiffening material and a method of manufacturing it.

Articles of clothing used to be stiffened mainly with woven horsehair inserts. More recently non-woven fabrics were also used for this purpose. Their manufacture is described in many places in the literature, as for example in US. Pat. Nos. 2,719,802, 2,719,803 and 2,719,806. These describe mats in which the fibers are bonded at their intersections with an elastic binding agent. The elastic binding agent gives appreciable resilience to these insert materials.

Thus, the stiffening materials comprise both woven goods (from light, open-weave cotton to heavy mohair interlinings) and non-woven fabrics (in wieghts between 20 and 200 g/m), which are partially coated with suitable thermoplastic adhesives such as highpressure and low-pressure polyethylene, PVC, lowmelting copolyamides and other such substances.

Originally the interlinings were sewn to the materiai being stiffened. For the past l5 years, approximately, iron-in interlinings have also been frequently used. To make them, they are dusted, in accordance with German Auslegeschrift No. l,096,324, with polyethylene powder which is then sintered.

It is obvious that a perfect cementing requires the most uniform possible distribution of the polyethylene grains. In practice, however, problems are repeatedly encountered. In case of trouble with the feeding apparatus, too much polyethylene is deposited in some places while others get virtually none at all. It is obvious that bonding the face material is impossible at places that have no polyethylene. Furthermore, delamination between the stiffening material and the face material began at voids of this kind. If, on the other hand, the stiffening material has too many adhesive granules, the adhesive strikes through the face material when it is ironed, resulting in hardening and in a spotty appearance.

To prevent the troubles that frequently result when the adhesive powder is sprinkled on, the printing of an adhesive paste onto the material in the form of regular dots was resorted to. German Auslegeschrift" No. 1,248,006 and US. Pat. No. 3,098,235 disclose such stiffening materials with uniformly printed dots. Here the distance of any dot from any adjacent dot is always the same. In this manner an absolutely uniform distribution of the binding agent is achieved. Overconcentration as well as under-concentration is avoided.

The application of dots of adhesive by printing methods represented an important improvement over the powder sprinkling process, because in contrast to the arbitrary distribution and accumulation of powder granules that is produced by powder sprinkling it made it possible to determine in advance the uniform arrangement of the dots, the dot spacing and the mass of the individual dot with great precision.

Dot spacing thus is important to the softness of the ironed laminate, while the mass of the individual dot, together with the physical and chemical properties of the thermoplastic employed, is responsible for the strength of adhesion. The maximum mass of the individual dots is limited by the danger that the adhesive may strike through the facing material or the support material, or the danger of excessive stiffness in the finished-ironed piece. The maximum spacing between the dots is determined by an increasing shimmer in the appearance of the facing due to the fact that tunnels may form between the interlining and the face material.

At the present time uniform, diagonally offset arrangements of rows of dots are used throughout the interlining manufacturing field, with dot spacing between 1.25 and 2.8 mm (from 20 to 9 mesh, mesh being the number of dots per inch along a row of dots, counting transversely or diagonally). Such interlining materials are the subject of Auslegeschrift" No. 1,248,006 and US. Pat. No. 3,098,235.

It is found, however, that precisely when such uniformly printed non-woven fabric stiffening inserts are used trouble may be encountered in the face material. Under certain lighting conditions, one gets the impression that the stiffened material is no longer smooth but is furrowed. This phenomenon is often particularly disturbing in fabrics in which either the warp threads or the filling threads are reinforced. Apparently the effect is produced when a row of dots of adhesive is located on a reinforcing thread in the fabric, and a raised line is created when the fabric is ironed. The space between two such lines may then be called a furrow.

Interference phenomena may also enter the picture, i.e. when such interlinings are ironed together with woven materials or fabrics having a corasely structured underside and a smooth face side, a phenomenon is observed which has long been referred to by textile printers as the moire effect. This effect in the printing of ink onto fabric is explained by the fact that different amounts of ink are transferred from the engraving on the printing cylinder according to whether the inkfilled point on the cylinder comes into contact with a high point or a low point on the fabric.

This moire-ing when it occurs in the large-area ironing of the coated interlinings onto coarsley structured textiles manifests itself not, of course, in a color change, but substantially in a shimmering appearance in the surface of the goods, caused by a shading action and occurring in the form of stripes and waves over the entire width of the piece.

Such pieces are unsuitable for use in articles of clothing.

The shimmering stripes and waves in textile laminates is apparently to be attributed to interference phenomena which develop when the printing screen is superimposed on the spacing of the fabric. They are strongest when the spacing of the printed dot pattern and that of the fabric structure is virtually the same and runs in the same direction. One might imagine that the interference could be prevented while maintaining the uniform pitched pattern of dots by selecting for each facing material an interlining material with a dot pattern as dissimilar as possible from the structure of the facing material. This, however, is impossible in practice due to the need to maintain too large a stock. In addition one must consider the amount of time lost due to the extensive experimenting that this requires.

The minimum and maximum spacing of the adhesive dots are rather narrowly restricted on the one hand by technical conditions relating to printing (eg. production of the stencil, clean formation of the image) on the one hand, and on the other hand by the requirements that must be met by the finished laminate (feel, surface appearance, adhesion).

It is accordingly an object of the present invention to print adhesive dots onto stiffening inserts in a manner which will avoid a moire effect, furrowing or other untoward effect in the apppearance of the fabric to which it is bonded.

These and other objects and advantages are realized in accordance with the present invention pursuant to which there is provided an iron-in stiffening insert com prising a support carrying a multiplicity of dots of adhesive arranged thereon in a random patern. Desirably, the average spacing between adjacent dots is no more than about greater or lesser than the average spacing between adjacent dots and the spacing between dots ranges from about I to 2.5 times the average diameter of the dots.

Thus, if a printed dot has a diameter of 0.86 mm, for example, the minimum distance to the next point is advantageously 1-1.4 mm, and the maximum distance 1.96 to 2 mm. Similarly, if it is desired, for example, to replace an interlining having a regular screen print of 13 mesh with one which will produce no interference phenomena, the spacing of the dots from one another should differ within a maximum range from about 1.8 to 2.0 mm in order to obtain the desired properties in the finished piece.

The simplest form of a pattern of the proposed kind is the arrangement of the dots in a statistically random distribution while preserving a predetermined maximum and minimum dot spacing. In addition, the desired irregularity is also favored by the selection of dots of different size, although the dot size may be varied only to a limited extent if the optimum adhesion is to be attained.

Additional patterns which are proposed for the avoidance of uniform linear dot arrangements are the arrangement of the dots in wavy lines running lengthwise, sideways or diagonally, and in polar shapes such as concentric circles or spirals, while maintaining the correct dot spacing. In the last-mentioned arrangement interference is impossible since a linear system (woven fabric) is being superimposed on a polar system (the adhesive dot pattern). A special embodiment is a combination of hexagons regularly or irregularly composed of dots and having sides deviating from the straight lines in all directions to assure the desired effect.

The invention will be further described with reference to the accompanying drawings wherein:

FIG. 1 is a plan view of a stiffening insert having adhesive dots randomly printed thereon; and

FIG. 2 is a plan view of another insert having a different pattern of adhesive dots printed thereon.

Referring now more particularly to the drawings in FIG. 1 there is shown a support 10 such as a non-woven staple fiber fabric carrying dots of polyethylene adhesive I2 thereon. The size of dots l2 and their spacings vary. Visibly the arrangement of dots is random although close inspection will reveal there is an infrequent repeat over a distance which is relatively large. Also the spacing between adjacent dots is never greater than about 2.5 times the dot diameter or less than about the dot diameter.

In FIG. 2 there is shown another support 20 carrying dots 22. The dots 22, however, are in small hexagonal clusters 24 which regularly repeat. This pattern is easier to imprint onto the roll which later prints the adhesive although its applicability is not as universal as is the FIG. I pattern. Within each hexagon 24 the size and spatial relationship of FIG. 1 still apply.

Fabrics stiffened by ironing-in of stiffened inserts as illustrated are free of undesirable furrowing and moire.

The invention is further illustrated in the following example.

EXAMPLE A non-woven staple fiber support sold under the trademark Vilene CX-3, weighing 50 g/m and 0.31 mm thick, can be printed with an aqueous polyethylene dispersion to apply 50 g/m of polyethylene. The dispersion is printed with a cylindrical roll in a pattern of dots of the size and spacing shown in FIG. 1. The support is permitted to dry and is then ironed with a flatiron onto a Tropical fabric weighing g/m and woven of a 50 50 blend of polyester and wool. The fabric face will show no patterns resulting from the insert.

It will be appreciated that the instant specification and examples are set forth by way of illustration and not limitation, and that various modifications and changes may be made without departing from the spirit and scope of the present invention.

What is claimed is:

1. An iron-in stiffening insert comprising a support carrying a multiplicity of printed dots of adhesive arranged thereon, the spacing between adjacent dots being non-uniform and no more than about 20% greater or lesser than the average spacing between adjacent dots and the average spacing between dots being non-uniform and ranging from about 1 to 2.5 times the average diameter of the dots.

2. An insert according to claim 1, wherein the dots are arranged on the support in wavy lines.

3. An insert according to claim I, wherein the dots are arranged on the support in polar configurations.

4. An insert according to claim 1, wherein the dots are arranged on the support as repeating geometrical clusters of adhesive dots randomly arranged within each geometrical repeat.

5. An insert according to claim 1, bonded to a facing fabric. 

1. AN IRON-IN STIFFENING INSERT COMPRISING A SUPPORT CARRYING A MULTIPLICITY OF PRINTED DOTS OF ADHESIVE ARRANGED THEREON, THE SPACING BETWEEN ADJACENT DOTS BEING NON-UNIFORM AND NO MORE THEN ABOUT 20% GREATER OR LESSER THAN THE AVERAGE SPACING BETWEEN ADJACENT DOTS AND THE AVERAGE SPACING BETWEEN DOTS BEING NON-UNIFORM AND RANGING FROM ABOUT 1 TO 2.5 TIMES THE AVERAGE DIAMETER OF THE DOTS.
 2. An insert according to claim 1, wherein the dots are arranged on the support in wavy lines.
 3. An insert according to claim 1, wherein the dots are arranged on the support in polar configurations.
 4. An insert according to claim 1, wherein the dots are arranged on the support as repeating geometrical clusters of adhesive dots randomly arranged within each geometrical repeat.
 5. An insert according to claim 1, bonded to a facing fabric. 